startup benchmark: enable category: navigation

This will make it easy to make a metric like request_start_time. I was
going to make it based on netlog, but that appears more difficult (many
events in netlog, etc). Also navigation events are generally useful for
startup, and not very frequent.

Bug: 760498
Change-Id: I7b9e9bb7efa0d4f2db729dafbb2b56e8ca1ec0ed
Reviewed-on: https://chromium-review.googlesource.com/955632Reviewed-by: Juan Antonio Navarro Pérez <perezju@chromium.org>
Commit-Queue: Egor Pasko <pasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542095}

tools/perf/benchmarks/start_with_url.py

@@ -91,8 +91,8 @@ class ExperimentalStartWithUrlCold(perf_benchmark.PerfBenchmark):
   def CreateCoreTimelineBasedMeasurementOptions(self):
     startup_category_filter = (
         chrome_trace_category_filter.ChromeTraceCategoryFilter(
-            filter_string=('loading,net,netlog,network,offline_pages,'
-                'startup,toplevel,Java,EarlyJava')))
+            filter_string=('navigation,loading,net,netlog,network,'
+                'offline_pages,startup,toplevel,Java,EarlyJava')))
     options = timeline_based_measurement.Options(
         overhead_level=startup_category_filter)
     options.config.enable_chrome_trace = True